Reporters and campaign staffers rush to their cars to get to Hillary Clinton's first Iowa campaign stop. Tamara Keith/NPR hide caption

itoggle caption Tamara Keith/NPR

Hillary Clinton has described herself as the most famous person you don't really know. And as she launches into her second presidential campaign, she'll be reintroducing herself to voters who largely think they have her figured out. Mel Evans/AP hide caption

itoggle caption Mel Evans/AP

Jeralean Talley addresses the congregation as her pastor, Reverend Dana Darby, holds the microphone for her during a celebration of her 115th birthday. Rebecca Cook/Reuters /Landov hide caption

itoggle caption Rebecca Cook/Reuters /Landov

Hillary Clinton in June 1969 at the Rodham family home. She was featured in a Life magazine story called "The Class of '69." Lee Balterman/The LIFE Premium Collection/Getty Images hide caption

itoggle caption Lee Balterman/The LIFE Premium Collection/Getty Images

Don't expect a big rally with thousands of cheering supporters to launch Hillary Clinton's campaign. For her second run at the presidency, she's out to prove she is taking nothing for granted. Yana Paskova/Getty Images hide caption

itoggle caption Yana Paskova/Getty Images

In April 1994, Hillary Clinton took questions from reporters for more than an hour as first lady. By that point, she had a reputation for not being particularly transparent and for not spending enough time addressing the national media. Doug Mills/AP hide caption

itoggle caption Doug Mills/AP

Former Florida Gov. Jeb Bush speaks to members of the media during a two-day swing through Iowa that had all the trappings of a presidential campaign. Charlie Neibergall/AP hide caption

itoggle caption Charlie Neibergall/AP